U 398
09:12 to 10:00
-39° to -50°
Ant, Vel
Jan - May

THE NORTHERN REACHES of the Sails encompass several interesting open clusters, presenting an observing challenge in several cases. Two MGC and 35 ESO/Upp galaxies dot this map, too faint for moderate-sized telescopes. A dozen planetaries (one of which is NGC 2792) also lie hidden on this Milky Way field.

The western edge of this chart shows Lambda Velorum, also called Alsuhail or Al Suhail al Wazn. To the naked eye, this bright (mv=2.2) star marks the far tip of the Southern Right-Angle, and to my eye has a distinct orange-yellow colour. The region surrounding Alsuhail, specially to the south and east, shows as a large mostly resolved glow, on one side of the Milky Way. It appears to be bound on the east and west by two massive, dark Milky Way dust lanes. In binoculars, the colourful Lambda is accompanied by a 4+ degree field of a dozen bright, scattered stars making an attractive sight.

Near the left edge of the chart lies m Velorum (09:52, -46°.5, mv = 4.6). Binoculars show a noticeable if sparse stellar grouping here. m Vel is accompanied by a half-dozen brightish stars, all of which are white, except m, which is clearly orange-yellow. Close to m is a small companion, which has the appearance of colour. I suspect this is an illusion, because of its proximity to the coloured m, and also because it is probably too faint for colour detection anyway.

FEATURED OBJECTS: ESO 261-SC007, Pismis 11, ESO 315-SC014, Ruprecht 160, Pismis 15, NGC 2849, NGC 2982, vdBH 63, Pismis 12, Ruprecht 81, NGC 2792, NGC 2932.

NGC 2932
RA 09:35:16
Dec -46° 57.0'
Open cluster

Discovered by John Herschel; in the Cape Observations he wrote: "This is about the middle of an enormous cluster of a degree or degree and half in diameter, very rich in stars of all magnitudes, from 8th mag downwards, which merits registry as a sort of telescopic Praesape. It may perhaps be regarded as a detached portion of the milky way, which is here very much broken up."

The RNGC (Sulentic and Tifft 1973) notes that this is a nonexistent object. Their coded description reads NOCL S.

11x80: A vague, coarse gathering of about 10 stars, half a degree across, only somewhat separate from the background. These few stars are fleshed out by nebulosity between the members. For comparison, within the field, just 1 degree west-southwest, lies a brighter grouping of stars, same size, but distinctly free of its neighbour's haziness. The whole area, for at least three degrees around, is littered with fine, small stars, making a milky rich field. (suburban skies, 6.0 naked eye) [AS]

6-inch f/8.6 Newtonian: Examined with 50' sweeper; nothing seen here resembling a cluster - perhaps my field is too narrow? (suburban skies, lim mag 6.0 (naked eye), seeing very good) [AS]

vdBH 63
ESO212-SC002
RA 09:20:36
Dec -49° 13.4'
Open cluster

Pismis 12
ESO261-SC005
RA 09:19:58
Dec -45° 06.7'
Open cluster

Ru 81
ESO262-SC003
RA 09:45:10
Dec -44° 06.0'
Open cluster

Not plotted on U398. Position taken from ESO/U, which shows it about a degree east of NGC 2982.

6-inch f/8.6 Newtonian: In the same low-power field as NGC 2982 and about a third of its size. 72-power shows it readily as a small, irregularly-round glow, like a very distant cluster. Reminds me of M44 with the naked eye. At 325x, there are 10 very small stars, perhaps more. Appears elongated (1:3) south-east to northwest, measuring 2.7' x 0.9'. (suburban skies, lim mag 6.0 (naked eye), seeing very good) [AS]

NGC 2792
ESO314-PN006, PK265+04.01
RA 09:12:25
Dec -42° 22.9'
Planetary nebula

In his diary, John Herschel - who discovered this objects - wrote: "planetary nebula, observed with Mr Maclear and another gentleman." His observing notes records it three times: first as "pF, exactly round, equal to a star 9th mag, but of a dull light. At first I was inclined to think it double, but with 320 it exhibited a uniform round disc; nor did a friend to whom I showed it see any division. Stars to-night perfectly well defined. In a field with leading stars, or which a diagram was made." On a second occassion he called it "pB, R, 6 arcseconds diameter, equals in light a star about 9th mag, a very careful and good observation." His third observation was recorded as "Viewed past meridian. It occurs in a field with about 40 stars. Diameter 4 or 5 arcseconds at the utmost; 10 arcseconds is too large certainly. Very like .. [NGC 2452]. But now the night is good and it bears magnifying. With 320 power the disc is dilated into a dim hazy round nebula; yet there is a peculiarity in its appearance which completely separates it from all nebulae of the same size. A very remarkable object."

Innes, in Union Obs. Circ., 1-44, p 345, notes: “An 11th mag. planetary nebula about 20’’ in diameter. Is N.pr. a pair of 10.5 mag stars. No stars within 3’. 1917, Mar. 16”

6-inch f/8.6 Newtonian: Easy starhop north-east of lambda Velorum. In a low-power sweeping eyepiece, the planetary is readliy seen as an 11th mag star on a rich field of mixed magnitudes. Within the higher-power 15' field, the planetary lies midway between two 9.5 mag stars (one north-west, one south-east). Midway between the pale round disk and one of the 95 mag stars is a small double star; the planetary is half the size of the separation of this double. Examined the disk at various powers, none of which show anything but an even, round disk. (suburban skies, lim mag 6.0 (naked eye), seeing very good) [AS]

ESO 261-SC007
RA 09:24:20
Dec -44° 42.4'
Open cluster

The ESO/U survey lists the cluster as measuring roughly 33' x 24' and comments: "class III3 Association?"

6-inch f/8.6 Newtonian: At 52x, the 40 arcmin field shows about 30 10th mag stars, then some 30 fainter ones. Massively scattered, but still a somewhat suspcious field, suggesting a real cluster. If all the stars were just 3 or 4 magnitudes brighter, you'd think it was NGC 2516, IC 2602, or some such.. (suburban skies, lim mag 6.0 (naked eye), seeing very good) [AS]

Pismis 11
vdBH 60, ESO 211-SC008
RA 09:16:41
Dec -49° 42.6'
Open cluster

Ru 160
ESO 262-SC011
RA 09:56:21
Dec -47° 02.1'
Open cluster

Not plotted on U398; co-ordinates taken from ESO/U.

6-inch f/8.6 Newtonian: The sweeper power (50', 43x) shows a quite evident coarse grouping of large and small stars. At 144x it is better seen. Besides the two brightish stars (shown on U398) there are about half-dozen fainter ones about in an east-west elongated grouping some 6' across (sketched). (suburban skies, 6.0 naked eye) [AS]

Pismis 15
ESO 212-SC010
RA 09:34:43
Dec -48° 02.3'
Open cluster

ESO 315-SC014
RA 09:35:24
Dec -39° 32.0'
Open cluster

6-inch f/8.6 Newtonian: This cluster is quite noticeable, clearly fuzzy, even in the sweeper eyepiece. Higher powers show a single 10th mag star surrounded by 5 very small stars (sketched). (suburban skies, 6.0 naked eye) [AS]

NGC 2849
Cr 207
RA 09:19:23
Dec -40° 31.0'
Open cluster

Discovered by Sir John Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it as "globular cluster, eF, R, vglbM; resolved into vS, but not very numerous stars; 2.5' diameter. It is rather a cluster of the 6th class than a globular cluster."

NGC 2982
Ru 80, ESO 262-SC001
RA 09:42:02
Dec -44° 00.8'
Open cluster

Discovered by Sir John Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it as "a cluster of about 20 stars 11th mag and two of about 10th mag, forming an oblong nearly in parallel; place of preceding star about 10th mag."

The RNGC (Sulentic and Tifft 1973) notes that this is a nonexistent object. Their coded description reads NOCL S.

11x80: Exactly midway between two 6/7th mag stars, one of which is y Velorum. The cluster appears as a very indistinct glow 10-15 arcmin across; very faint and hazy on a milky, rich, background. At first, it looks (irregularly) round; with some studying, looks slightly elongated, east-west, perhaps 1:2. The four-degree binocular field is rich and textured and the cluster doesn't have enough contrast to stand out well. (suburban skies) [AS]

6-inch f/8.6 Newtonian: Seen in the low-power sweeper as a coarse, medium grouping of about 15 stars of the 11th magnitude. Fits comfortably into 15 arcmin field of view (sketched). (suburban skies, 6.0 naked eye) [AS]

Coloured Stars

Lambda Vel: orange-yellow
m Vel: orange